Effects of different monoamine oxidase inhibitors on respiratory activity in rats with chronically impaired central serotonergic function.
Resting and CO2 stimulated respiration were measured by means of a whole-body plethysmograph in rats lightly anaesthetized with halothane. Rats pretreated neonatally with intracisternal 5,7-dihydroxytryptamine (5,7-DHT) to destruct permanently central serotonergic neurones had significantly lower resting and CO2 stimulated respiratory frequency (RF) and minute volume (VM) than naive rats. In the 5,7-DHT pretreated rats, but not in naive rats, the monoamine oxidase inhibitors clorgyline and pargyline further reduced both resting and CO2 stimulated RF and VM, whereas 1-deprenyl stimulated respiration. The results provide additional evidence that monoaminergic mechanisms are involved in central modulation of respiration in which activation of a serotonergic neuronal system depresses, and dopaminergic activation stimulates respiration.
D015116:5,7-Dihydroxytryptamine / Q000494:pharmacology; D000818:Animals; D001679:Biogenic Amines / Q000378:metabolism; D001784:Blood Gas Analysis; D001923:Brain Chemistry / Q000187:drug effects; D002245:Carbon Dioxide / Q000494:pharmacology; D006439:Hemodynamics / Q000187:drug effects; D008297:Male; D008784:Methysergide / Q000494:pharmacology; D008996:Monoamine Oxidase Inhibitors / Q000494:pharmacology*; D051381:Rats; D012119:Respiration / Q000187:drug effects*; D012701:Serotonin / Q000502:physiology*
D001679:Biogenic Amines; D008996:Monoamine Oxidase Inhibitors; D002245:Carbon Dioxide; D015116:5,7-Dihydroxytryptamine; D012701:Serotonin; D008784:Methysergide